office



C. E. JOHNSON AND N. E. BROWN.

BRAZED ROTOR CUNSTHUCHON.

APPLICAHON FILED JUNE 1. I920.

Patented Oct. 31, 1922.

INVENTORS CARL E. JOHN SON NICHOLAS E. BROWN 7 ATTQRNEYJ L To all it maybonoei'ms man i w sse L lssisnons'wo' 'n; siiiilntitniohr.

tal man mower; ,*9.. pe ins l M-ANU'EACT RING CO AiCOBPORATION OFB'R'KZED ROTOR CGNSTRUCTIUN.

Be it known thafl tteyflfim niJmaasdm and Nriinoinil'siEi Biiowiijibbthcitizens of the Ufi'iteii 'States,-"rsidii1g at Los Angeles, county ofLos Angeles, and State of California, have invented a new and useful Improvement in Brazed Rotor Constructions, of which the following is aspecification.

My invention relates to dynamo electric machinery and is particularlyapplicable to induction motors having a bar type secondary or rotor.Such rotors consist of a series of annular sheet steel punchings built vup on a shaft and perforated with slots near the periphery through whichconductors pass. These conductors are joined at each end to a common endring. For the purpose of insuring a good conductivity at the junctionbetween the end rings and the corduct-ing bars, it is common practice tobraze the bars to the end rings and our invention relates morepaiticularly to the method of securing the bars to the end rings so asto insure a perfect joint therewith and to provide a mechanicalconnection which will mechanically hold the bars and end ring t getherindependent of said brazing.

Further objects and advantages will he made evident hereinafter.

Referring to the drawing which is for illustrative purposes only,

Fig. 1 is a side view of the portion of a rotor embodying my invention.

Fig. 2 is a view on an enlarged scale showing the finished joint betweenthe end ring and the conductor.

F ig. 3 is a diagram showing the form of the bar and end ring beforethey are secured together.

Fig. 4: is a section on a plane represented by the line 44 of Fig.2.

In the form of the invention shown. punehings 11 are assembled on theshaft 12 having slots through which conducting bars 13 extend, thesebars projecting beyond the unchings at either end thereof. .15 initiallyformed, each of the bars 13 has a rertangular slot 15 formed therein.End rings 16 are provided at each end of the rotor, these end ringshaving a cylindrical ridge 17 formed. on the side thereof. this ridgebeing of keystone shape so that the point 18 is somewhat thicker thanthe base 19. The method of assembling the rotor is as follows:

placed.iwi tli t he ridge 1 fin the sloth-15 Pressure is iheii tpplredin l the directieii ot the arrows A-A of Fig. 2 thus bending theportions of the bars 13 on either side of the slot 15 and forcing theminwardly so that they are mechanically interlocked with the ridge 17 andin the position shown in Fig. 2. The bar 13 is then brazed to the endring 16 and the ridge 17, the brazing mate rial being shown in black at20 in Fig. 2. The bars used are preferably of keystone shape as shown inFig. 4, but bars having parallel sides with or without rolled edges mavbe used if desired.

t will be noted that by the use of our invention it is possible tomechanically interlock the bars 13 with and secure them to the end ring16 quite independent of the brazing material and if considerablepressure is exerted along the direction of the arrow AA, a quiteintimate contact is produced between the end of the bar 13 and the ring16. It is possible by the use of this method to secure both end rings tothe bars very solidly so that the brazing operation is greatlyfacilitated and so that the completed rotor has very great mechanicalstrength.

I claim as my invention:

1. In a dynamo electric machine, the combination of a slotted core,conducting bars extending through and projecting from the slots in saidcore at either end thereof, each end of such bar having a slot formedtherein. and two conducting end rings, each end ring have a cylindricalridge formed thereon of proper diameter to fit in the slots in one endof each bar havinga slot formed therein. said ridge being thicker at thepoint than at the base so that the bars may be mechanically interlockedtherewith independent of said brazing.

2. In a dynamo electric machine, the combination of a slotted core.conducting bars extending through and projecting from the slots in saidcore at either end thereof, each end of each bar having a slot formedthere in. and two conducting end rings, each end ring, having acylindrical ridge formed thereon of proper diameter to fit in the slotsin one end of all the bars and be brazed thereto, said ridge beingthicker at the point than at the base so that thebars may be distortedto mechanically engage therewith independent of said brazing.

3. In a dynamo electric machine, the combination of a slotted core;conducting bars extending through and projecting from the slots in saidcore at either end, thereof, each end of each bar having an openingformed therein; and an end ring of substantially T shaped section havingone branch of said T fitting in said openings, the branch of, said Tfitting in said openings, beingth-ioker at its outer end than at itsbase-s0 that the endsof theibars maybe crimped thereon.

1. In a dynamo electric machine, the combination of'a slotted core;conducting 'bars extending through and projecting from the slots in saidcore at either end thereof, each end of each bar having an openingformed therein; and an end ring having a lgeystonevshaped section fittinin said openings, the ends of the bars being bent down to erimppmsaidkeystone section.

In testimony whereof, We have hereunto set our hands at Los Angeles,California, this26thday of-Ma 1920.

CA L E. JOHNSON. NICHOLAS E. BROWN.

